In the present study we will measure and compare the unbound, i.e. microbiologically active concentrations of doripenem after a single dose of 500mg in plasma, subcutaneous adipose tissue and muscle tissue and saliva of healthy volunteers. We will use the microdialysis technique, which allows for the continuous measurement of unbound drug concentrations in the interstitial space fluid. The findings of the present study will help to assess whether currently employed therapy regimens with doripenem provide effective antimicrobial concentrations in different compartments in man